In recent years, due to the development of electronic information technology, the miniaturization and densification of electronic equipment installation, the large capacity of information, the high frequency and high speed of transmission signals, and the fact that the transmission lines of electronic circuit board applied in the hardware devices of the high-end communication network such as routers, switches and servers, etc. become longer and longer, the electronic circuit substrate is required to have a lower dielectric constant and a lower dielectric loss.
For high-speed electronic circuit substrate, during its long-term use, maintaining the stability of the dielectric constant and the dielectric loss of the substrate will produce a significant impact on the change in characteristic impedance and the signal integrity of the substrate. The stability of the dielectric constant and the dielectric loss contains three aspects: temperature drift, wet drift and thermal-oxidative aging resistance of the dielectric constant and the dielectric loss.
For the thermal-oxidative aging property, in the resin curing system of a substrate, both the dielectric constant and the dielectric loss of the substrate will increase since the thermal-oxidative aging will occur during the long-term use of the resin, thereby affecting its stability, the signal integrity of the substrate will be deteriorated ultimately. Therefore, the good thermal-oxidative aging resistance of the resin curing system of a substrate is an important performance requirement for the high-speed electronic circuit substrate.
Because the acrylate group-modified thermosetting polyphenyl ether resin contains a large number of benzene ring structure without strong polar group in its molecular structure, which imparts excellent properties to the polyphenyl ether resin, such as high glass transition temperature, good dimensional stability small thermal expansion coefficient, low water absorption, especially outstandingly low dielectric constant and low dielectric loss, it becomes the ideal resin material for the preparation of the high-speed circuit substrate.
Since the vinyl resin crosslinking agent such as butadiene-styrene copolymer has no polar group in its molecular chain structure, it has excellently low dielectric constant and low dielectric loss, and is usually used as a crosslinking agent for the preparation of the high-speed circuit substrate.
CN103965606A discloses a low-k material comprising: 40 to 80 parts by weight of polyphenyl ether; 5 to 30 parts by weight of bismaleimide; and 5 to 30 parts by weight of a polymeric additive. The polyphenyl ether used in the disclosure is a bifunctional acrylate group-modified thermosetting polyphenyl ether resin, and the polymeric additive comprises a hydrocarbon resin such as polybutadiene and butadiene-styrene copolymer, which can be used for the preparation of the high-speed circuit substrate.
CN102807658A discloses a group of polyphenyl ether resin composition comprising: a functionalized polyphenyl ether; a crosslinking curing agent; and an initiator. The polyphenyl ether used in the disclosure is a bifunctional acrylate group-modified thermosetting polyphenyl ether resin, and the crosslinking curing agent comprises a hydrocarbon resin such as polybutadiene and butadiene-styrene copolymer, which can be used for the preparation of the high-speed circuit substrate.
CN101589109A discloses a group of polyphenyl ether resin composition comprising: a functionalized poly(arylene ether); a vinyl thermosetting resin; and a flame retardant composition. The polyphenyl ether used in the disclosure is a bifunctional acrylate group-modified thermosetting polyphenyl ether resin, and the vinyl thermosetting resin is such as polybutadiene and butadiene-styrene copolymer, which can be used for the preparation of the high-speed circuit substrate.
The above related technics have the following problems: in order to obtain a lower dielectric constant and a lower dielectric loss, it is necessary to increase the use ratio of the vinyl resin crosslinking agent such as polybutadiene. The bifunctional acrylate group-modified thermosetting polyphenyl ether resin has a limited number of acrylate groups, which is unable to make an excess amount of double bonds on the side chains of the vinyl resin crosslinking agent such as polybutadiene react completely, although the prepared substrate has a lower dielectric constant and a lower dielectric loss. The incompletely reacted double bonds on the side chains of the vinyl resin crosslinking agent such as polybutadiene has poor thermal-oxidative aging resistance, which can seriously affect the stability of the dielectric constant and the dielectric loss of the substrate during the long-term use, thereby deteriorating the signal integrity of the substrate, so that the customers' needs cannot be satisfied.